docs: def closest_length(refs, pred):
      '''
      >>> closest_length(['1234', '12345', '1'], '123')
      4
      >>> closest_length(['123', '12345', '1'], '12')
      1
      '''
      smallest_diff = float('inf')
      closest_length = float('inf')
      for ref in refs:
          diff = abs(len(ref) - len(pred))
          if diff < smallest_diff or (diff == smallest_diff and len(ref) < closest_length):
              smallest_diff = diff
              closest_length = len(ref)
      return closest_length